It has been suggested that nanopores in thin membranes can be used to detect and characterize nucleic acids polymers DNA and RNA, including their nucleotide sequence [1]. In the very basic setup, a lipid bilayer membrane containing a single nanopore in it is submerged in electrolyte solution containing dissolved analyte molecules. External electric field forces charged analytes to transit the nanopore from one side of the membrane to the other, modulating the current of ions flowing through the nanopore. It has been shown that biological nanopores MspA [2] and alpha-hemolysin [3] can be used to read out the sequence of single DNA strands as modulations of the ionic current if the transport of DNA through the nanopores is controlled by auxiliary protein motors such as a DNA polymeraze.
Nanopores in solid-state membranes are thought to have even greater potential for biosensing applications, as they exhibit superior mechanical properties and can be straightforwardly integrated with conventional electronics for large array multiplex detection. However, the common problem with using solid-state nanopores for DNA sequencing and other biosensing applications is the lack of control over the transport of DNA through the nanopores. Typically, the DNA transits a solid-state nanopore too fast for its sequence to be detected by a physical measurement.